LIVE BETTER: How Blue Light Actually Affects Your Sleep

Sleep is one of those things we can take for granted—and it’s something I didn’t appreciate until I hit my mid 20s. I remember waking up super early to start on my to-do list, feeling like sleeping in was a huge waste of time. It wasn’t until the demands of my to-do list grew to the point where I was barely able to keep up that I realized I needed to start prioritizing my sleep.        

We are in the age of “rise and grind”, where being a “hustler” is celebrated. This hustler attitude means people are trying to maximize their productive time by staying up late and getting up early—i.e. skimping on sleep.   

We are also constantly overstimulated, thanks to technology. How many times have you helplessly watched as a Netflix episode autoplayed, dictating that (no matter how sleepy you might be) your bedtime would be delayed by another half hour at least?    

This, in combination with the cultural tendency to not prioritize sleep, isn't just detrimental to sleep quantity. It can cause our sleep quality to decline, too. Losing just one night of sleep can make us irritable, crave sweets, decrease our cognitive ability, increase inflammation, and can lead to brain fog. And you can't trick the system. Some people feel that they can catch up on sleep over the weekend to make up for poor sleep habits during the work week, but this idea of catching up isn’t beneficial for our bodies long term. Our bodies accrue "sleep debt", and that debt can become monumental over time. In fact, this cycle of poor sleep during the week can lead to increased pain sensitivity, body discomfort, GI upset, mood changes and more.     

How Light Dictates Your Sleep Schedule  

Your circadian rhythm (the internal clock that governs your sleep/wake cycle) is driven by light and dark. There are cells in the retina of your eye that are connected to the suprachiasmatic nucleus (SCN), which acts as the pacemaker of the circadian rhythm. Light increases cortisol where darkness increases melatonin. Cortisol should peak in the morning and should drop to its lowest levels around 10pm. Melatonin on the other hand is produced by the pineal gland. The pineal gland is turned on by the SCN (in complete darkness), which will increase melatonin levels.  

If your room is not dimly lit, it will be tricked into thinking that it’s daytime. This is how light can throw off your circadian rhythm and melatonin levels. Blue light from your computers, phones or TV can mimic morning light and suppress your melatonin production. I recommend that people get seven to nine hours of sleep per night, so what is a working professional suppose to do? Ideally, you would be off of your screens and devices before bed and instead be sipping on chamomile tea while reading a book or trying a meditation app… but I know that this isn’t always realistic, so I have a few expert hacks you can try.   

How to Work Around Blue Light at Night   

  1. Use blue light filtering glasses. I first heard about this option when I was completing my undergraduate degree. My professor at the time introduced the idea of shift workers benefiting from these glasses as a way to combat ‘light at night” (LAN). This conversation had started due to the WHO classifying “shift-work that involves circadian disruption” as a possible carcinogen in 2007. However, not all blue light blocking glasses are created equal. Some glasses are coated/ tinted, which can make them less effective and cause colors to be distorted. It’s best to look for "blue light filtering glasses".  
  2. Download f.lux: f.lux adjusts the color of your computer screen to mimic the time of day. The screen will be warmer at night, blocking out the blues, and brighter in the morning.  
  3. Invest in black out curtains. Small amounts of light can affect melatonin production. Black out curtains help to ensure that street lights, traffic lights etc. don’t pour into your room and disrupt your circadian rhythm.  
  4. Turn the glow of your digital clock away from your face… if you still use one of those in this day and age! Every little bit of light matters.

5 Other Science-Backed Ways to Support Sleep

1. Melatonin. As mentioned before, melatonin is a hormone produced by your pineal gland and plays a huge role in regulating your circadian rhythm. Small doses of melatonin may help those who have already perfected their sleep hygiene. 

2. Avoid sleep antagonists:

      • Evening coffee. This leads to an increase in your adrenaline, which decreases sleep quality. 
      • Late night workouts. Try and workout before 8pm so as to not overstimulate your body or surge your cortisol levels.  
      • Alcohol. This may be something that helps you unwind after a busy day, but alcohol can block REM sleep.   

      3. Optimize your gut health. The connection between your digestive health and sleep quality is complicated and continuously expanding. The microbiome (the community of microbes living in your gut) can affect your sleep by influencing your circadian rhythm. Just as the microbiome can influence your sleep quality, poor sleep can also influence the health of your microbiome. There are several conditions such as: acid reflux, SIBO, and IBS that can alter your digestive health which can play a role in sleep loss. 

      4. Stress management. Cortisol should be at its highest in the morning. Elevated nighttime cortisol may be a cause of poor sleep and cortisol dysregulation may be a cause of waking up unrefreshed and having that evening energy dip.   

      5. Invest in a good pillow and mattress. A comfortable and cozy bed can go a long way when it comes to falling asleep easily. You spend a third of your life there, after all.     

      Resources:

      Chung et al.  (2017) Cooperative roles of the suprachiasmatic nucleus central clock and the adrenal clock in controlling circadian glucocorticoid rhythm. Sci Rep. 

      Irwin et al. (2016) Sleep Disturbance, Sleep Duration, and Inflammation: A Systematic Review and Meta-Analysis of Cohort Studies and Experimental Sleep Deprivation. Biol Psychiatry. 

      Kantermann et al. (2009) Is light-at-night a health risk factor or a health risk predictor? Chronobiol Int 26(6): 1069- 74. 

      National sleep foundation (2019) Retrieved from: https://www.sleepfoundation.org/articles/how-much-sleep-do-we-really-need 

      Shinomiya, et al. (2005) Hypnotic activities of chamomile and passiflora extracts in sleep-disturbed rats. Biol Pharm Bull: 28 (5): 808-10. 

      Simpson et al. (2018) Chronic exposure to insufficient sleep alters processes of pain habituation and sensitization. Pain. 

      Thaiss, et. al. (2014) Transkingdom Control of Microbiota Diurnal Oscillations promotes metabolic homeostasis. Cell. 159(3):514-529

      Voigt, et. al. (2014) Circadian disorganization alters intestinal microbiota. PLoS ONE 9(5).

      About the Author: 

        Dr. Krista Lowe is a good friend of our queen bee Carly and is a BKN ambassador. She is an expert in health and wellness and is a Naturopathic physician practicing out of Tall Tree Health in Victoria, BC. You can find her on Instagram  @natmedicine.